Cards (3)

  • How is TB spread?
    • Via droplet infection
    • MB Inhaled into lungs
  • Describe primary infection
    • MB triggers non-specific response
    • Phagocytosis
    • MB engulfed by macrophage
    • MB produces a chemical that stops lysosome fusion
    • So MB isnt destroyed by immune system
    • Stays dormant because:
    -Releases chemical that stops lysosome fusion
    -Hides inside macrophage -> specific IR isnt stimulated
    -Very waxy cell wall, hard to break down
    • MB proliferates inside macrophage
    • Contained by Th cells
    • Forms granuloma
  • Describe secondary infection
    • If immune system weakens
    • MB inside granuloma reactivates
    • Bursts out of granuloma
    • Infects other parts of lung -> damaged
    • Can spread to other organs via blood -> organ failure
    • Possibly death